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Regular expression: Use this field, if the user's input should be checked with a RegEx validation. If desired you can add an regular expression error message as well.
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Choose this column type, if you want to select an existing Jira user. If you want the mentioned user to receive a notification mail go to → Manage and check the checkbox:
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Select List
Here you can create a drop-down select list. To manage and create options, click on → Manage. The following screen will appear and will let you define the possible amount of selections and of course to add new options to choose from:
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